#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<math.h>

int main()
{
	double n = 0;
	int m = 0;
	while (scanf("%lf %d", &n, &m) != EOF)
	{
		int i = 0;
		double sum = 0.0;
		double next_n = 0.0;

		for (i = 0; i < m; i++)
		{
			sum = sum + n;
			n = sqrt(n);
		}

		printf("%.2f\n", sum);
	}

	return 0;
}